lndclient: add closed channels to lnd client

Author: carlaKC

lndclient/lightning_client.go

@@ -50,6 +50,9 @@ type LightningClient interface {
 	// ListChannels retrieves all channels of the backing lnd node.
 	ListChannels(ctx context.Context) ([]ChannelInfo, error)
 
+	// ClosedChannels returns all closed channels of the backing lnd node.
+	ClosedChannels(ctx context.Context) ([]ClosedChannel, error)
+
 	// ChannelBackup retrieves the backup for a particular channel. The
 	// backup is returned as an encrypted chanbackup.Single payload.
 	ChannelBackup(context.Context, wire.OutPoint) ([]byte, error)
@@ -109,6 +112,138 @@ type ChannelInfo struct {
 	Uptime time.Duration
 }
 
+// ClosedChannel represents a channel that has been closed.
+type ClosedChannel struct {
+	// ChannelPoint is the funding outpoint of the channel.
+	ChannelPoint string
+
+	// ChannelID holds the unique channel ID for the channel. The first 3
+	// bytes are the block height, the next 3 the index within the block,
+	// and the last 2 bytes are the output index for the channel.
+	ChannelID uint64
+
+	// ClosingTxHash is the tx hash of the close transaction for the channel.
+	ClosingTxHash string
+
+	// CloseType is the type of channel closure.
+	CloseType CloseType
+
+	// OpenInitiator is true if we opened the channel. This value is not
+	// always available (older channels do not have it).
+	OpenInitiator Initiator
+
+	// Initiator indicates which party initiated the channel close. Since
+	// this value is not always set in the rpc response, we also make a best
+	// effort attempt to set it based on CloseType.
+	CloseInitiator Initiator
+
+	// PubKeyBytes is the raw bytes of the public key of the remote node.
+	PubKeyBytes route.Vertex
+
+	// Capacity is the total amount of funds held in this channel.
+	Capacity btcutil.Amount
+
+	// SettledBalance is the amount we were paid out directly in this
+	// channel close. Note that this does not include cases where we need to
+	// sweep our commitment or htlcs.
+	SettledBalance btcutil.Amount
+}
+
+// CloseType is an enum which represents the types of closes our channels may
+// have. This type maps to the rpc value.
+type CloseType uint8
+
+const (
+	// CloseTypeCooperative represents cooperative closes.
+	CloseTypeCooperative CloseType = iota
+
+	// CloseTypeLocalForce represents force closes that we initiated.
+	CloseTypeLocalForce
+
+	// CloseTypeRemoteForce represents force closes that our peer initiated.
+	CloseTypeRemoteForce
+
+	// CloseTypeBreach represents breach closes from our peer.
+	CloseTypeBreach
+
+	// CloseTypeFundingCancelled represents channels which were never
+	// created because their funding transaction was cancelled.
+	CloseTypeFundingCancelled
+
+	// CloseTypeAbandoned represents a channel that was abandoned.
+	CloseTypeAbandoned
+)
+
+// String returns the string representation of a close type.
+func (c CloseType) String() string {
+	switch c {
+	case CloseTypeCooperative:
+		return "Cooperative"
+
+	case CloseTypeLocalForce:
+		return "Local Force"
+
+	case CloseTypeRemoteForce:
+		return "Remote Force"
+
+	case CloseTypeBreach:
+		return "Breach"
+
+	case CloseTypeFundingCancelled:
+		return "Funding Cancelled"
+
+	case CloseTypeAbandoned:
+		return "Abandoned"
+
+	default:
+		return "Unknown"
+	}
+}
+
+// Initiator indicates the party that opened or closed a channel. This enum is
+// used for cases where we may not have a full set of initiator information
+// available over rpc (this is the case for older channels).
+type Initiator uint8
+
+const (
+	// InitiatorUnrecorded is set when we do not know the open/close
+	// initiator for a channel, this is the case when the channel was
+	// closed before lnd started tracking initiators.
+	InitiatorUnrecorded Initiator = iota
+
+	// InitiatorLocal is set when we initiated a channel open or close.
+	InitiatorLocal
+
+	// InitiatorRemote is set when the remote party initiated a chanel open
+	// or close.
+	InitiatorRemote
+
+	// InitiatorBoth is set in the case where both parties initiated a
+	// cooperative close (this is possible with multiple rounds of
+	// negotiation).
+	InitiatorBoth
+)
+
+// String provides the string represenetation of a close initiator.
+func (c Initiator) String() string {
+	switch c {
+	case InitiatorUnrecorded:
+		return "Unrecorded"
+
+	case InitiatorLocal:
+		return "Local"
+
+	case InitiatorRemote:
+		return "Remote"
+
+	case InitiatorBoth:
+		return "Both"
+
+	default:
+		return fmt.Sprintf("unknown initiator: %d", c)
+	}
+}
+
 var (
 	// ErrMalformedServerResponse is returned when the swap and/or prepay
 	// invoice is malformed.
@@ -583,6 +718,130 @@ func (s *lightningClient) ListChannels(ctx context.Context) (
 	return result, nil
 }
 
+// ClosedChannels returns a list of our closed channels.
+func (s *lightningClient) ClosedChannels(ctx context.Context) ([]ClosedChannel,
+	error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, rpcTimeout)
+	defer cancel()
+
+	response, err := s.client.ClosedChannels(
+		s.adminMac.WithMacaroonAuth(rpcCtx),
+		&lnrpc.ClosedChannelsRequest{},
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	channels := make([]ClosedChannel, len(response.Channels))
+	for i, channel := range response.Channels {
+		remote, err := route.NewVertexFromStr(channel.RemotePubkey)
+		if err != nil {
+			return nil, err
+		}
+
+		closeType, err := rpcCloseType(channel.CloseType)
+		if err != nil {
+			return nil, err
+		}
+
+		openInitiator, err := getInitiator(channel.OpenInitiator)
+		if err != nil {
+			return nil, err
+		}
+
+		closeInitiator, err := rpcCloseInitiator(
+			channel.CloseInitiator, closeType,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		channels[i] = ClosedChannel{
+			ChannelPoint:   channel.ChannelPoint,
+			ChannelID:      channel.ChanId,
+			ClosingTxHash:  channel.ClosingTxHash,
+			CloseType:      closeType,
+			OpenInitiator:  openInitiator,
+			CloseInitiator: closeInitiator,
+			PubKeyBytes:    remote,
+			Capacity:       btcutil.Amount(channel.Capacity),
+			SettledBalance: btcutil.Amount(channel.SettledBalance),
+		}
+	}
+
+	return channels, nil
+}
+
+// rpcCloseType maps a rpc close type to our local enum.
+func rpcCloseType(t lnrpc.ChannelCloseSummary_ClosureType) (CloseType, error) {
+	switch t {
+	case lnrpc.ChannelCloseSummary_COOPERATIVE_CLOSE:
+		return CloseTypeCooperative, nil
+
+	case lnrpc.ChannelCloseSummary_LOCAL_FORCE_CLOSE:
+		return CloseTypeLocalForce, nil
+
+	case lnrpc.ChannelCloseSummary_REMOTE_FORCE_CLOSE:
+		return CloseTypeRemoteForce, nil
+
+	case lnrpc.ChannelCloseSummary_BREACH_CLOSE:
+		return CloseTypeBreach, nil
+
+	case lnrpc.ChannelCloseSummary_FUNDING_CANCELED:
+		return CloseTypeFundingCancelled, nil
+
+	case lnrpc.ChannelCloseSummary_ABANDONED:
+		return CloseTypeAbandoned, nil
+
+	default:
+		return 0, fmt.Errorf("unknown close type: %v", t)
+	}
+}
+
+// rpcCloseInitiator maps a close initiator to our local type. Since this field
+// is not always set in lnd for older channels, also use our close type to infer
+// who initiated the close when we have force closes.
+func rpcCloseInitiator(initiator lnrpc.Initiator,
+	closeType CloseType) (Initiator, error) {
+
+	// Since our close type is always set on the rpc, we first check whether
+	// we can figure out the close initiator from this value. This is only
+	// possible for force closes/breaches.
+	switch closeType {
+	case CloseTypeLocalForce:
+		return InitiatorLocal, nil
+
+	case CloseTypeRemoteForce, CloseTypeBreach:
+		return InitiatorRemote, nil
+	}
+
+	// Otherwise, we check whether our initiator field is set, and fail only
+	// if we have an unknown type.
+	return getInitiator(initiator)
+}
+
+// getInitiator maps a rpc initiator value to our initiator enum.
+func getInitiator(initiator lnrpc.Initiator) (Initiator, error) {
+	switch initiator {
+	case lnrpc.Initiator_INITIATOR_LOCAL:
+		return InitiatorLocal, nil
+
+	case lnrpc.Initiator_INITIATOR_REMOTE:
+		return InitiatorRemote, nil
+
+	case lnrpc.Initiator_INITIATOR_BOTH:
+		return InitiatorBoth, nil
+
+	case lnrpc.Initiator_INITIATOR_UNKNOWN:
+		return InitiatorUnrecorded, nil
+
+	default:
+		return InitiatorUnrecorded, fmt.Errorf("unknown "+
+			"initiator: %v", initiator)
+	}
+}
+
 // ChannelBackup retrieves the backup for a particular channel. The backup is
 // returned as an encrypted chanbackup.Single payload.
 func (s *lightningClient) ChannelBackup(ctx context.Context,

test/lightning_client_mock.go

@@ -175,6 +175,13 @@ func (h *mockLightningClient) ListChannels(ctx context.Context) (
 	return h.lnd.Channels, nil
 }
 
+// ClosedChannels returns a list of our closed channels.
+func (h *mockLightningClient) ClosedChannels(_ context.Context) ([]lndclient.ClosedChannel,
+	error) {
+
+	return h.lnd.ClosedChannels, nil
+}
+
 // ChannelBackup retrieves the backup for a particular channel. The
 // backup is returned as an encrypted chanbackup.Single payload.
 func (h *mockLightningClient) ChannelBackup(context.Context, wire.OutPoint) ([]byte, error) {

test/lnd_services_mock.go

@@ -163,7 +163,8 @@ type LndMockServices struct {
 	// keyed by hash string.
 	Invoices map[lntypes.Hash]*lndclient.Invoice
 
-	Channels []lndclient.ChannelInfo
+	Channels       []lndclient.ChannelInfo
+	ClosedChannels []lndclient.ClosedChannel
 
 	WaitForFinished func()